A protective chair having a base with a support platform having supporting legs extending therefrom to hold the platform and an engaged seat cushion elevated from a support surface. The brightness at least of those base colors of the control light is varied, whose dynamics in the recorded image go beyond the admissible dynamic range. In one embodiment, an internal U-shaped connector is positioned to engage the seam flanges while an external U-shaped connector covers the internal connector and the seam between adjacent glazing panels. The free end of the arms are arranged to function as an electrical grounding tang in the operative position of the connector assembly.